(The) + coffee

Hi,

I am having a hard time finding a definite answer to this question.

At a supermarket:

Customer: "Where can I find (the) coffee?"

Is the definite article required? I was told by several people that you need to use it. But my English textbooks have different examples where the article is omitted.

Example #1 from one of these books: "Where can I find milk?" A: "In the dairy department."

Example #2: Teddy: "Excuse me, where can I find canned soup?" A: "Canned soup is down aisle two . . ."

To my ears it sounds natural to say "where can I find coffee" and omit the article. It sounds like "where can I find (some) coffee (in this supermarket)?". What am I missing?